John Deere 2407.03 – BLC: Outer Worklights on Rear of Roof, External Voltage

The Roof Lighting Control Unit (RLC) has detected voltage on the rear roof outer work light circuit when the light is commanded to be off. This indicates a voltage backfeed or a short to a high source in the wiring loom, meaning electrical potential is present on the wire leading to the light fixture despite the switch or control module being turned off.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6090MC
• 6090RC
• 6100MC
• 6100RC
• 6110MC
• 6110RC

1. 1

   Perform switch circuit tests (S092-2 or S092-4) to ensure the cab switch is not internally shorted and bleeding power to the circuit.

2. 2

   Disconnect the rear roof outer work lights and check the BLC output pin with a multimeter. If voltage is still present with the lights unplugged and the switch off, the short is in the wiring loom.

3. 3

   Trace the roof wiring harness back to the BLC, looking closely for pinched wires, melted insulation, or chafing where the harness routes through the cab pillars or roof structure.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the negative battery cable to prevent accidental shorts during testing.

2. 2

   Access the Roof Harness

   Remove the rear roof liner/paneling to access the wiring harness connecting the BLC to the rear outer work lights.

3. 3

   Inspect and Repair Wiring

   Visually inspect the loom for damage. If a short to power is found (e.g., a bare work light wire touching a constant 12V wire), cut out the damaged section of the wire and splice in a new section using weather-sealed heat-shrink butt connectors.

4. 4

   Test the Switch

   If the wiring is intact, remove the rear work light switch from the side console/dash. Use a multimeter to check for continuity across the switch terminals when it is in the 'OFF' position. If continuity is found, the switch is internally shorted and must be replaced.

5. 5

   Replace Damaged Harness

   If the roof wiring loom is severely melted or damaged beyond a simple splice repair, replace the affected work light wiring harness section.

6. 6

   Reassembly and Verification

   Reconnect the work lights, reinstall the roof panels, and reconnect the battery. Turn the tractor on, leave the work lights off, and verify that the BLC no longer detects voltage on the pin. Clear the 002407.03 fault code using a diagnostic tool.